package com.sloera.nowcoder;

import java.util.HashSet;
import java.util.Scanner;

/**
 * class com.sloera.nowcoder
 * user sloera
 * date 2022/2/22
 */
public class HJ9 {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        // 注意 hasNext 和 hasNextLine 的区别
        while (in.hasNextInt()) { // 注意 while 处理多个 case
            int a = in.nextInt();
            reverse(a);
        }
    }

    private static void reverse(int a) {
        final String s = String.valueOf(a);
        final HashSet<Character> set = new HashSet<>();
        for (int i = s.length() - 1; i >= 0; i--) {
            if (!set.contains(s.charAt(i))) {
                System.out.print(s.charAt(i));
                set.add(s.charAt(i));
            }
        }
    }
}
